Compilare: user.cpp: In function ‘long long int solve(int, int)’: user.cpp:47:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < y.size(); ++ i) ^ user.cpp:48:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = i + 1; j < y.size() && j - i <= 8; ++ j) ^ user.cpp: In function ‘int main()’: user.cpp:56:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmap.in", "r", stdin); ^ user.cpp:57:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmap.out", "w", stdout); ^ user.cpp:60:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp: In member function ‘void POINT::read()’: user.cpp:15:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &x, &y); ^